486 Scientrfic Intelligence. 



Merrillite, a meteoritic calcium phosphate. Described by G. 

 P. Merrill in Proc. Nat. Ac. Sc, i, 302, 1915; this Journal, xliii, 

 322, 1917. Considered by E. T. Wherry (Am. Min., ii, 11-9, 

 1917) as an independent species and given the above name. 

 Similar to franeoUte but differs in important features. Biaxial, 

 positive. Comp. — xCd^O.yVfi^. 



Spencerite. Previously described by T. L. Walker (Min. Mag., 

 xviii, 76, 1916) and an abstract given in a previous list, has lately 

 been found in crystals. Walker (Jour. Wash. Ac. Sc, vii, 456, 

 1917) gives the following new facts: Monoclinic. a:b:c=^ 

 1-0125 : 1 : 1'0643, P = 63° 13'. The crystals are small and 

 tabular parallel to (100). Crystals are twinned on (100). Some 

 twenty forms were observed of which the most important are, 

 (100), (110), (120), (010), (001), (102), (101), (221), (241). 



Crestmoreite. A. S. Eakle, Univ. Cal. Publ., x, 344, 1917. 

 An alteration product of loilkeite. Compact. Color, snow-white. 

 Luster vitreous to dull. Fuses quietly and easily. H. = 3. 

 G. = 2*22. Easily soluble with separation of a small amount of 

 flocculent silica. Shows parallel extinction, positive elongation, 

 low birefringence, ^8=1 '59. Analysis shows it is a hj^drous 

 calcium silicate with small amounts of phosphate, sulphate and 

 carbonate molecules. The latter radicals are considered to be 

 small portions of those in the original wilkeite. The true compo- 

 sition of the mineral is taken to be approximately A:}lfi2i^\0 ^. 

 3H2O. Found in the blue calcite at Crestmore, Riverside County, 

 California. 



Riversideite. A. S. Eakle, Univ. Cal. Publ., x, 347, 1917. 

 Occurs in compact fibrous veinlets traversing massive vesuvianite. 

 Silky luster. H. =3. G. = 2*64. Fusible at 2 to a white glass. 

 Easily soluble leaving flocculent silica. Parallel extinction. 

 Fibers elongated parallel to c. a = 1*595, y = 1'603. A hydrous 

 calcium silicate, 2CaSiO.H20. Analysis shows also small amounts 

 of phosphoric and sulphuric acids. Found at Crestmore, River- 

 side County, California. 



2. Descriptive Mineralogy ; by William Shirley Bailey. 

 Pp. xvii, 542; 268 figures. New York, 1917 (D. Appleton and 

 Co.). — Professor Bailey has written this book, as he says in its 

 preface, "with the purpose of affording a student a comprehen- 

 sive view of modern mineralogy rather than a detailed knowledge 

 of many minerals. The minerals selected for description are not 

 necessarily those that are most common nor those that occur in 

 greatest quantity. The list includes those that are of scientific 

 interest or of economic importance, those that illustrate some 

 principle employed in the classification of minerals." In addition 

 to the body of the work which gives the descriptions of individual 

 species there are short and excellent chapters on the composition 

 and classification of minerals; the formation of minerals and their 

 alterations; general principles of blowpipe analysis; characteristic 

 reactions of the more important elements and acid radicals; also 



